High Availability solutions

Hi

We are using in our company an ERP system called iScala.

This software is using SQL server as DBMS.

We would like to use the SQL mirroring feature from SQL 2005.

The software is using the SQL server instance name to connect to databases and when the Main SQL server fails the application can't connect to the Mirror instance.

Unfortunatelly we can't change the connection string (the software is provided by another company).

Do you have a solution?

Thanks

I believe you have to contact the vendor to provide such changes, as this is application issue to talk to the mirror server in the event of failover. If the application is not db mirror aware then you have to find a route from connectivity to talk to other server in such cases.|||

Thanks

You are right.

I'm checking now some solutions for High Availability from Symantec (VERITAS Storage Foundation HA 4.3 for Windows) and Double-Take.

Do you have any information about them?

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You could solve this issue using a manual change to DNS.

i.e. MYLIVESQL -> 10.0.0.1 - connection string uses MYLIVESQL as the server name, in the event of a failure you update the DNS record to MYLIVESQL -> 10.0.0.2 (which is the IP address of the mirror server).

Andrew

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If the (former) principal instance is still up and running but the database failover occured, then SNAC will automatically learn the location of the mirror and redirect the connection to the mirror, as described here: http://msdn2.microsoft.com/en-us/library/ms366348.aspx. But this works only if the connection string specifies the database and if the principal instance is still running.

But if the vendor is not providing support for mirroring, is highly unlikely that the application will actually work with mirrored database, it may have dependencies outside the database that are not gonna failover (e.g. logins resulting in orphaned users, jobs in msdb etc)

HTH,
~ Remus

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Remus,

MOSS 2007 and WSS V3 fall into the category of not supporting mirroring in the connection strings, hence the need to use the cname approach. Microsoft recommend using stsadm to manually change the settings which I think is less elegant.

Andrew